As an operating speed of a semiconductor memory device has increased, swing widths of signals interfaced between the semiconductor memory device and a memory controller have decreased. A reason for the decrease of the swing widths is to reduce the time required to transmit the signals. However, as the swing widths have decreased, the signals transferred between the semiconductor memory device and the memory controller may be more easily distorted and reflected. To improve the distortion of the transferred signals, the semiconductor memory device may include an on-die termination (ODT) circuit that provides a signal transmission line with a termination resistance component for impedance matching. The ODT circuit may reduce (and/or prevent) the signals from being reflected by using the termination resistor so as to improve signal integrity, however, power consumption may increase due to an ODT operation performed by the ODT circuit. Researchers are conducting various research projects on techniques of reducing the power consumption and improving the signal integrity.